In pop culture Vampire teeth are often assumed/shown to be just like human teeth except that they have fangs instead of canines. After spending way too much time in front of the mirror, making weird faces, I have come to the conclusion that the canines are too far back in the mouth to be properly placed for biting. However, due to the amount of orthodontia work I've been through, the amount I still have to go through, and the fact that I've never bitten anyone to drink their blood, I have no idea if this is correct.

Tell me if I'm wrong or not

• If I'm wrong, explain why the canines are ideally placed for biting


• If I'm right, explain where in the human mouth the fangs should be placed, with explanation


• Or redesign a human looking mouth/set of teeth with fangs that with exception of the fangs looks human at a glance to a non-dentist or non-vampire hunter

Criteria

• Exactly two fangs


• Resulting puncture wounds should be about (but not absolutely required) an inch apart to match most pop culture depictions


• Must be ideally placed to puncture blood vessels in human neck (preferably the jugular)


• Can be any two teeth, in the top and or bottom row, but both in the top row preferred, and horizontal symmetry preferred


• Blood (human) is the only food the vampire(s) needs to eat, fangs can interfere with or completely prevent consumption of any other food or liquid

Probably important things that I'd rather you ignore for sake of questions I'm planing on turning this into a series with

• Length




• Retract-ability




• Do they actually suck the blood via the teeth, or just puncture the skin

Related

Convenient teeth for a bloodsucking vampire

Especially the first answer

Recap

Where should Vampire fangs be located in a (probably) human mouth?

Try biting yourself with just enough force to leave a mark. It'll probably look like this:

You can see the canines' marks, but not the molars.

Molars won't reach, they're out of the question. So thw decision must be made between incisors and canines.

If you pierce the skin with incisors, more blood will fall out of your mouth than if you pierced with the canines. They are the teeth farthest back to hit, so piercing with them keeps more blood in the mouth.

So I think the classical notion of canines is best, but with a twist: by making the lower canines the vampiric teeth rather than the upper ones, you can collect even more blood successfully.

Actual vampire bats have their teeth (the inner pair of upper incisors) modified, not as puncturing fangs, but as slashing blades. They feed by slicing away a strip of skin and lapping the blood that flows out, with an anticoagulant property of their saliva preventing premature clotting.

This type and location of fangs seems most convenient for any mammal. With a little modification of facial shape (to allow the teeth to clear the nose), this would work very well for a humanoid vampire. Better by far than puncturing and trying to suck through the resulting wounds.

All you really need is one fang to pierce the cartoid artery. The bodys own blood pressure will literally pump the blood right into your vampiric mouth.

The problem with fangs in the upper jaw is that a puncture from a bite would pierce the skin at an angle. This poses the risk of you not being able to capture all the blood, leaving behind a mess and making you extremely suspicious.

Since the lower jaw is much more flexible, the chances of making a neat, staight hole is much higher. The tongue - that can aid you in finding the right angle to bite - is also positioned in the lower jaw and at a perfect position to feel your lower fangs and whatever they're biting into.

As for the best angle of the fangs in a vampire's mouth, it seems that slightly pointing forward (out of the mouth) would yield the best results.

• Inward pointing fangs are perfect for holding slippery prey (think of shark's teeth), but they pierce the skin at an angle that is not best for catching the blood flowing out.


• Straight teeth are common in predators that need to hold onto their prey but also kill it with a bite to the jugular. They seem to be the most utilitarian solution for a vampire as well.


• Outward pointing teeth are plain weapons (think of wild boars) but to be suited for a vampire, the angle cannot be too flat. The vampire could pierce an artery with great precision and have the blood flow directly into his mouth. He could control the blood flow by only partially retracting his teeth from the puncture wound.

But which teeth should it be?

I think any pair of teeth from the central incisors up to the canines would be suitable. The incisors probably more so, because they are at the very front of the mouth and the tongue could guide the teeth to their target with greater precision if they are both within range of the tip of the tongue at the same time. The canines are too far apart for that.

Summary:
The fangs of a vampire should be a pair of incisors in the lower jaw that slightly points forward (out of the mouth).

Reframe: why just teeth?

Honestly, the whole “vampire teeth” thing never really clicked for me. As noted by @Zeiss Ikon, actual vampiric mammals don’t use teeth to puncture skin, but to tear the skin. Human teeth are relatively fragile, and would be even moreso if elongated enough to overcome natural skin elasticity and drive past the surrounding, lesser teeth. You’re asking to have your main feeding instrument snapped off by struggling prey, and gating your entire ability to feed on the presence of just two teeth.

Use your tongue

Cats, large and small, have papillae on their tongues, little spine like things. On a little cat, this makes their tongue feel like sandpaper. On big cats, it’ll take your skin off in two swipes.

If you have a tongue like that, it will give you a much wider surface area to get blood from, so you don’t have to depend on hitting an artery. If you have to have puncture wounds, then a pair of only-slightly-longer canines in the bottom jaw will help you hang onto squirming prey, without needing long-and-fragile teeth. Punctures will be coincidental to the feeding, and thus, even elderly vampires who have lost teeth will get to feed as usual.

Bonus: it’s much easier to go incognito. The spines on the tongue retract, and less pronounced fangs will keep you safe from hunters.

As has been pointed out, molars won't work - they are too far back.

If you think about it, any position forward of the canines won't work either - they will interfere with speech, specifically the interdental fricative. Try making a prolonged "th" sound, and feel where your tongue is extending beyond your front teeth.

Your "Must be ideally placed" requirement is difficult to understand, except as it seems to favor forward teeth. While the external jugular is probably the target for the vampire bite marks I've seen (in the movies, of course - what did you think I meant?), the internal jugular and carotid arteries are actually a good deal more convenient, being located just behind the trachea. These vessels are more convenient in the sense that they don't require a vampire to open as wide, although they do require longer fangs.